[Gnuplot-info] plotting a knot on a torus

[Brian M. <bhm...@gm...>]

I plotted a torus, and a knot on it, using the following commands:

unset key
set parametric
set isosamples 30,30
set hidden3d
splot [-pi:pi][-pi:pi] (2 + cos(u))*cos(v), (2 + cos(u))*sin(v), sin(u),
[-pi:pi] (2 + cos(u))*cos(u), (2 + cos(u))*sin(u), sin(u)

This works beautifully.

However, if I plot a more complicated knot:

splot [-pi:pi][-pi:pi] (2 + cos(u))*cos(v), (2 + cos(u))*sin(v), sin(u),
[-pi:pi][-pi:pi] (2 + cos(3*u))*cos(2*u), (2 + cos(3*u))*sin(2*u), sin(2*u),

then the knot's curve breaks :(  It seems this has something to do with
`set hidden3d`, as if I unset that, then nothing is hidden, but the curve
is rendered normally.

What can I do to fix this problem?

I am on Windows 10, using the latest version of gnuplot, with the Qt
terminal.

Kind regards,
Brian